Copernicus

The sky is the roof of human life and has been since man first lifted himself off his knuckles. He has always had ideas about that roof, and they have become more marvelous rather than less. This should confound those who believe that Change and Hopelessness go hand in hand. Who would not agree that an expanding universe with countless fires is a more wonderful place to live in than any cosmic scheme that went before it?

Yet in our pride of knowledge, we should not dismiss the most primitive concepts as the fairy tales of man’s infancy. They were attempts to explain things, and they used what knowledge was available. It is a salutary exercise to think, sometimes, how we ourselves should fare if we stood where our ancestors did.

Take the ancient Egyptians, for example. If you were an Egyptian, you knew that the level of the Nile rose when a star called Nephthys’ Tear fell into the river. This was a thing, like the passage of the sun across the sky, that a man could see for himself. There were ceremonies to be performed when the star fell — that is, dropped below the southern horizon — and your mind was never clear whether the ceremonies made the river rise, or whether the star would fall if the river didn’t rise, and so on. There was one thing you would never think, that the position of the star and the rise of the Nile were coincidental. It couldn’t be coincidence, not if you felt the unity of things, the overriding human necessity of finding a link between separate phenomena.

You were never quite sure, of course, how long the year was. You were confused by the time the sun took to get across the sky in his boat — how else could it cross all that blue, waterlike stuff? — and the time the stars took to get across it. So your year was never quite long enough. You got to 365 days but were beaten by the bit left over. If a man thinks the computation should be easy, he should try doing it in ancient Egyptian, with a system of numbers even clumsier than the Roman. So the calendar was wrong and stayed that way, and the ceremonies connected with the seasons drifted farther away from them, until after about a thousand years they had worked right through the calendar. As a failure in astronomical prediction, it was spectacular.

The first step toward a rational account of the sky — one depending on observation — was taken by the Greeks. We must talk about them, since an essentially Greek view of the universe dominated Western thought until the seventeenth century. Their arguments were, as one would expect, reasonable. Clearly, the sky is the abode of God; and since God is perfect, so must the sky be. What figure is more perfect than the sphere? However you turn a sphere about its center, it remains changeless in every part. Moreover, it is obvious to naked-eye observation that the heavens are spherical. If you doubt that, go out and look at them. So all the movements in the sky must be circular, or the result of some complex of circular movements. It stands to reason. As for the spheres themselves, they must be made of some changeless crystalline substance; for they look just like that.

The man who gave definition to this system was Ptolemy, the greatest astronomer of the ancient world, who lived in the second century after Christ. His system endured without much alteration for nearly fifteen hundred years. The spheres were concentric, the moon moving in one, the sun in another, planets in yet more, and the stars in the last one on the outside. The earth was a globe at the center, motionless at the heart of all this movement. It must be motionless; otherwise an arrow shot straight up would not return to the bowman. When all these spheres moved over each other — since God’s sky must be perfect — they did not grate like cartwheels but made heavenly music. This, too, was reasonable.

Certain wild philosophers had suggested that the earth itself rotated — had suggested, indeed, that the sun might stand still and the earth move around it, but their ideas never made any headway. The weight of common-sense opinion was too heavy, where there was no possibility of proof. This is one example of the social pressures on astronomers: even when they were ahead of the rest of humanity, they could not convince men before they were ready to be convinced. We can see in this the operation of that most mysterious and elusive thing, the climate of popular opinion. For thousands of years, astronomy had to accord, more or less, with the experience of the uninformed common man. No philosopher who proposed a radical change was persecuted; he was simply ignored, and his ideas disappeared or remained unread in some forgotten manuscript.

So the Ptolemaic system, with its reliance on the fairly accurate, but limited ideas of Aristotle, triumphed because people were prepared to accept it as a useful summation of the universe. Nevertheless there remained unsolved problems. More accurate observation showed that only the stars have the perfect circular movement. The planets, the wanderers, do not conform to it. If you look at a planet at midnight and remember where it stood among the stars, then midnight by midnight you will see how it has shifted among them, drifting westward. In time, each planet will drift right across the sky. More than this, a planet sometimes seems to slow down, stop, reverse its direction, stop again, then drift westward once more. These movements have always seemed significant to man — but how can they be called perfect? How, in other words, can the astronomer reduce these random movements to the circular movement which alone was thought worthy of God? What is more, if he cannot account for them, he cannot predict them — and bang! goes the calendar.

Yet with all these shortcomings, there was a very good reason why the system held the field for so long. By the end of the fifth century the Roman Empire was tottering, and its fall brought in a dark age that lasted for nearly a thousand years. Men had little time or inclination to think of the physical heavens. All they wanted was security, and the finite crystal spheres gave them the feeling of it. Nor could an astronomical team assemble — astronomy has usually been a matter of teamwork, for all its many great names — because Europe was splintered and travel was a dangerous adventure. So for that thousand years, the Ptolemaic system staggered on, emended, elaborated, but never seriously questioned. Indeed, with the rise of the Catholic Church, prediction was frowned on, since it was closely linked with astrology, which seemed to deny man’s free will by giving him a predestined future. Astronomy remained intellectually frozen.

There were two forces that tended all the time to unfreeze it. One was the given nature of man. Faced nightly with an appallingly beautiful and inexplicable phenomenon, some men could not but wonder, examine, speculate — though no one realized that what was wanted was an imaginative break-away from the whole system. The second freeing force was what we might call a practical matter. With the fading of the Dark Ages, commerce revived; and commerce needs an accurate calendar. The law itself was at stake. How are you going to enter into an agreement with someone for a number of years if you don’t know how long a year is? Machines were being invented. Voyages of discovery were acquainting men with new places and new ideas. The speculations of the ancients were being rediscovered.

The creaking calendar had become such an irritant that the Pope himself finally looked around for a competent astronomer who was as little contaminated by astrology as possible. He settled on a canon of the cathedral of Frauenburg, who was also a doctor of canon law, a doctor of medicine, business executive of the cathedral chapter, an amateur painter, and a passionately interested astronomer in his spare time. But when the canon read the Pope’s appeal to him, he asked to be excused.

The canon’s name was Nikolaus Koppernigk. By birth he was either Pole or German — the argument is endless. It seems likely that Nikolaus himself would be uninterested in the question. He would have thought of himself not as a Pole or German but as a Catholic. His father was a businessman in Prussian Poland, and Nikolaus was born at Thorn; but in his youth he was virtually adopted by his uncle, the Bishop of Ermeland. From that time forward his life lay between the chapter houses of cathedrals and the high tables of the universities. He never became a priest, but always and wholly he was of the Church.

He was a serious-minded young man and very much an intellectual. Yet looking at the early portraits of him, one wonders. There is a kind of sensitivity about the face that could well belong to another sort of person. Sometimes, in the early woodcuts, he holds a lily in his left hand. One has preposterous memories of Oscar Wilde walking down a London street with a lily in his hand; and there is a minor sense in which there may be some connection. If Koppernigk was not an aesthete in the nineteenth-century sense, I believe, nevertheless, that the key to an understanding of his work is that it was aesthetic.

However this may be, his uncle recognized his intelligence and sent him off to be educated; and henceforth his name was no longer Polish/German Koppernigk but Latin Copernicus, as befitted a man who had joined the supremely supranationalistic organization of the Catholic Church. He studied mathematics first. Then, at the age of twenty-three, he went for further study to Bologna, where he was deflected toward astronomy by the lectures of one Domenico da Novara. This was not necessarily a profound study, since a certain acquaintance with the crystal spheres (still endlessly revolving) was a part of every young man’s education. He studied medicine too, and canon law. It was a time when the sum of knowledge was not too wide for one intellect and one memory. Did not Faust take all the doctorates and apply to the devil for more knowledge when he had learned all that anyone else could teach him? But Copernicus was no Faust. Two doctorates were enough, though he was to change the world far more than Faust did. Copernicus was austere, controlled and reliable. When he went back to Poland, it was to an appointment as personal physician to his uncle.

That is the visible total of what happened to Copernicus in Italy; but there is something more hinted at, and when we know what that is, we may fancy that we can find traces of it written in his face. The Renaissance had brought to Italy all the precious wisdom of the ancient world. Men were prepared to ask questions again, perhaps even to try all things and hold fast to that which is good. Copernicus met Neoplatonists in Italy, and Neopythagoreans — men ready for the adventures of philosophical speculation with no holds barred. These men knew — for they were responsible teachers — that it was a dangerous business, not necessarily for the philosopher himself but for those little ones who might be taught; that the new ideas must go no farther than the few people qualified both to understand them and to bear their implications.